Astrology is the science of the soul, based upon the precise movement of planets within the Zodiac Belt.
The Zodiac Belt
The Zodiac is a belt on the celestial sphere containing the twelve constellations. The stars and planets which form the pattern in each constellation are way beyond our solar system.
This belt should not be confused with the part of the sky (ecliptic) containing the twelve segments of space, called the signs of the zodiac through which our solar system travels.
The ecliptic is the elliptical path the Sun, Moon and planets travel round, as experienced or seen from earth. It is a 360° circle through which the planets travel at varying distances from each other. As they travel round the circle they pass through the 30° segments (signs of the Zodiac) of the circle at different speeds and times. The Sun, of course, travels round the whole circle passing through all the 30° segments (or signs) in one year.
The 30° portions of the sky (or signs) where first identified as fixed and separate influences by Ptolemy in 178 AD. They were named after the constellations because of the patterns of the stars that could be seen in the sky beyond.
It is these twelve equally divided portions of the sky that make up the twelve signs of the zodiac, not the constellations beyond them (a common misconception). The circle created by these twelve segments is called the Tropical Zodiac.
As we all know, the planets and the Moon all orbit the Sun, but for the purposes of astrology, we have to imagine that the earth is at the centre of the solar system with the Sun and planets orbiting us as the earth turns on its axis.
As the Sun and planets move, they are seen against the background of the ecliptic as they progress through the 30° segments or signs and therefore, will be in one or other of the twelve segments at any given time.
The first sign is Aries, starting the 360° circle at 0°s Aries. This is because it is at this point that the Sun’s path on the ecliptic intercepts or crosses the equator into the northern hemisphere on the 21st of April, (the Spring or vernal equinox).
This was seen to be symbolically the start of new growth and rebirth. The opposite point, or halfway round the circle, is 0°s Libra. It is at this point that the Sun again crosses the equator, this time into the southern hemisphere, (the Autumnal equinox)